1. Technical Field
The present invention relates to a fuel tank cap and, more particularly, to a fuel cap designed for an internal combustion device and featuring easy operation, leakage prevention, and dust-proofness.
2. Description of Related Art
Portable internal combustion devices, such as mowers, blowers, tree felling machines, chainsaws, outboard motors, and so forth, rely on the ignition and combustion of fuel oil in engines to drive cranks and thereby output power. To facilitate fuel refill, the fuel tank of a common internal combustion device is typically provided with a refill opening closed by a fuel tank cap. Due to cost considerations, the fuel tank caps of commercially available internal combustion devices usually adopt an internally and externally threaded structure and are connected to the refill openings by threaded engagement.
While the internally and externally threaded structure provides the intended securing effect, the most complained-about drawback of such threaded connection is that the operator has to rotate the fuel tank cap continuously until the fuel tank cap is removed from or seals the refill opening. Apart from the inconvenience of operation, the conventional fuel tank caps lack an anti-leak structure and may therefore lead to a spill of fuel from the fuel tanks when the internal combustion devices are shaken during operation. Besides, external liquid may also enter the fuel tanks through the fuel tank caps and damage the internal combustion devices as a result. Moreover, the existing fuel tank caps are very likely to be lost, for there are no proper places where they can be put after they are screwed out of the refill openings.